I want to find the interstitial positions for Cd_3P_2 unit cell. I tried in online, but it is limited for 8 atoms per unit cell. Cd_3P_2 unit cell has 40 atoms. So, I could not succeeded. Can you help me in this regard?. Please find the attachments.

We limit the AFLOW-online tool in this case because these calculations can become expensive. Please download the full AFLOW binary here for un-throttled functionality: http://materials.duke.edu/AFLOW/.